GIS stands for Geographic Information System.
A GIS allows us to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts. It captures, stores, analyzes, manages, and presents data that is linked to location. Technically, GIS is geographic information systems which includes mapping software and its application with remote sensing, land surveying, aerial photography, mathematics, photogrammetry, geography, and tools that can be implemented with GIS software...


Some GIS-related sites:

2009 Disease maps

Terra Server

Air Quality

Dynamic Maps

Crime Map

Google Maps